This invention is in the field of machines used to inspect the alignment and location of various articles. Metal-working machines, including milling and similar machines, may be arranged in line with the workpiece moving past each machine in turn providing a specific machining operation upon the workpiece. Such an arrangement of machines is referred to as a transfer line. As the workpiece moves from one machine station to the next machine station of the transfer line, it is imperative that the individual machine stations be aligned and correctly located relative to the center fixture of the transfer line to insure achievement of the desired tolerances. The individual machine stations must be aligned when initially set up for operation. In addition, it is sometimes necessary to realign the work station after the transfer line has been used over a period of time. Currently with existing techniques, each individual machine station may be located and aligned in approximately eight to ten hours. By utilizing the device disclosed herein, it is possible to reduce the individual machine station alignment time to approximately two hours.
There are a number of devices which include inspection probes movable in the X, Y and Z axes. For example, the U.S. Pat. No. 3,279,079 issued to F. S. Schiler discloses an inspection probe mounted to a plurality of carriers allowing for a three-axis movement of the probe. Another approach to a three-axis inspection or measuring machine designed by F. S. Schiler is shown in U.S. Pat. No. 3,279,077. In lieu of moving the probe in all three axes, it is possible to move the probe in only two axes and instead move the workpiece in the third axis. Such an approach is shown in the U.S. Pat. No. 3,813,789 issued to Russell S. Shelton. The same Russell S. Shelton also discloses in his U.S. Pat. No. 3,840,993 a coordinate measuring machine having a probe which is movable in any of the three mutually perpendicular directions.
It can be appreciated that the alignment of one work station to another work station within a transfer line is extremely critical with a very small range of allowable error. For example, if a first work station is to provide a machining operation such as drilling a hole in a workpiece, and if the next work station is to provide another machining operation in the same hole, then it is imperative that the spindles of both machines be correctly aligned and located or else the workpiece will be improperly machined.
Typically, the prior coordinate measuring or inspection devices utilize a probe mounted to a first carrier vertically slidable upon a second carrier. The second carrier while slidable in, for example, the horizontal X direction, is in turn mounted to yet a third carrier which is horizontally slidable in the Z direction and eventually resting upon and supported by the bearing surface located upon the datum base of the transfer line center fixture. The margin of error is increased by such an approach utilizing three carriers sequentially slidable upon the adjacent carrier. The inspection machine disclosed herein mounts the vertical Y axis rail directly upon the horizontal bearing surface of the bearing plate in turn mounted to the center fixture of the transfer line. The vertical Y axis rail may be moved along both the Z and X horizontal axis rail but is independent thereof insofar as the Y axis rail is supported directly upon the horizontal bearing surface. The structure further allows the vertical Y axis rail and X axis rail to be lifted upwardly and removed from the bearing plate in a relatively easy manner thereby facilitating removal of the inspection machine from one location to another location.
In certain instances, the inspection of the location and alignment of the machine station by the heretofore available inspecting machines will indicate the spindle of the machine as correctly located when in fact the axis of rotation of the tool held by the spindle will be skewed. The machine disclosed herein includes a plurality of probes movable along the length of the tool held by the spindle thereby allowing comparison between the X and Y coordinates of one end of the tool as compared to the X and Y coordinates of the opposite end of the tool. In addition to the aforementioned advantages, the machine disclosed herein may be used to check not only individual work stations but also to check the dimensions of the actual workpiece produced by the transfer line.